Cashiers call me a '*****'

A cap I wanted to buy was labelled with a price of R40 (I have photo's). The cashier said the price is R140 when scanned but I asked why is it labelled R40. I requested to speak to the manager, the manager said that it is definitely supposed to say R140 but I can take it for R40. The cashier then waits for the manager to leave and continues to scan the cap for R140 after the manager already gave her an instruction. The cashier then told me that Im being '*****', how can I want to take the cap for R100 off the price. I told her that the manager gave the go ahead. She said no she will NOT scan it for that price. I then asked to use a different cashier and she also said that I am wrong for wanting to take the cap for that price. IF IT IS MARKED R40 THEN THATS WHAT I AM PAYING!! How the F can the staff call me *****?? Im highly disgusted and I feel like I was belittled!